WO2005054363A1

WO2005054363A1 - Liquid fluoropolymer composition and process for producing crosslinked fluorochemical

Info

Publication number: WO2005054363A1
Application number: PCT/JP2004/017889
Authority: WO
Inventors: Takuya Arase; Masayoshi Tatemoto
Original assignee: Daikin Industries, Ltd.
Priority date: 2003-12-01
Filing date: 2004-12-01
Publication date: 2005-06-16
Also published as: US7847001B2; JP4839837B2; US20070141425A1; JP5573246B2; JPWO2005054363A1; US20100080931A1; JP2010180408A

Abstract

A liquid fluoropolymer composition which comprises a fluoropolymer fluid comprising a liquid medium and a crosslinkable fluoropolymer, characterized in that the fluoropolymer fluid is a liquid fluoropolymer dispersion comprising a liquid dispersion medium and, dispersed therein, particles of a crosslinkable fluoropolymer having an acid/acid salt group or an organic group which, upon hydrolysis, is converted to carboxy or the fluoropolymer fluid is a fluoropolymer solution comprising a fluorochemical solvent or alcohol/water mixed solvent and, dissolved therein, a crosslinkable fluoropolymer having an acid/acid salt group or a precursor for the group, and that the acid/acid salt group is sulfo, carboxy, -SO2NR2R3, -SO3NR4R5R6R7, -SO3M11/L, -COONR8R9R10R11, or -COOM21/L and the precursor is -SO2F, -SO2NR22R23, or an organic group which, upon hydrolysis, is converted to carboxy.

Description

Specification

Fluorine-containing polymer liquid composition and process for producing fluorinated crosslinked product

Technical field

The present invention relates to a fluoropolymer liquid composition and a method for producing a fluorinated crosslinked product.

Background art

A polymer electrolyte fuel cell, which has been receiving attention in recent years, has a problem that is lower than the power of which a fluorine-containing electrolyte membrane is mainly used. In order to improve the power generation characteristics of the fuel cell, there are methods such as increasing the ion exchange capacity of the electrolyte membrane and decreasing the film thickness, but all of these methods result in a decrease in mechanical strength. Because the membrane is strongly tightened during use, the membrane is deformed and deteriorated due to creep phenomena, and the membrane swells and shrinks when power generation is stopped. Become.

[0003] In order to prevent the deterioration of the fluorine-containing electrolyte membrane, it has been proposed to crosslink the electrolyte membrane to form a crosslinked membrane (see, for example, Patent Documents 1, 2, 3, 4, 5, 6, and 7). ) ₀ as a method for obtaining the crosslinking film, a method of melt-extruding a mixture of a榭脂and crosslinking agent are known. However, since the cross-linking reaction occurs even in the molding machine, it is difficult to control the cross-linking reaction, and it is difficult to produce a film of stable quality!

[0004] As preparation of crosslinked fluorine-containing electrolyte membranes, a method of hot-press molding a mixture of a榭脂a crosslinking agent are also known (e.g., see Patent Document 6.) While ₀ tooth force, film large size Is difficult to obtain, and batch production is required, which makes mass production difficult.

[0005] As a method for producing a cross-linked fluorine-containing electrolyte membrane, a method is known in which a perfluoro-based sulfonyl fluoride film formed as usual is impregnated with a cross-linking agent, and then cross-linked by heating or high energy rays (for example, Patent Document 5.) ₀ However, this document does not disclose cross-linking by heating or the like after forming a cast film with a solution. Further, the cross-linking agent is generally a large molecule, and it is difficult to impregnate the inside of the film uniformly, and there is a problem that it is difficult to obtain a uniform cross-linked film.

[0006] As a method for producing a cross-linked fluorine-containing electrolyte membrane, a cross-linking agent is mixed with one SOF type dispergillon. It is known that after casting, a film is formed and then crosslinked by heating (for example, Patent Document

See 7. ;). However, there is a problem that the emulsifier and the initiator residue remain in the single-SOF type disparge, and the properties of the obtained film are deteriorated.

Patent Document 1: JP-A-60-133031

Patent Document 2: JP-A-54-107889

Patent Document 3: JP-A-54-52690

Patent Document 4: JP-A-61-276828

Patent Document 5: JP-A-2000-188013

Patent Document 6: JP-A-2002-53619

Patent Document 7: JP-A-2003-128833

Disclosure of the invention

Problems to be solved by the invention

[0007] In view of the above situation, an object of the present invention is to provide a polymer having an acid-acid salt type group, which is excellent in mechanical properties by being crosslinked after being applied to a substrate or impregnated in a porous material, and having a high water content. Means for Solving the Problems The object of the present invention is to provide a liquid composition capable of producing a crosslinked product having a small dimensional change.

[0008] The present invention is a fluoropolymer liquid composition comprising a liquid medium and a crosslinkable fluoropolymer having a crosslinkable functional group (A).

The fluorine-containing polymer liquid (A) contains particles of a cross-linkable fluorine-containing polymer (PD) having an acid salt type group or an organic group which is converted into a carboxyl group by hydrolysis in a liquid dispersion medium. Liquid fluoropolymer dispersion (AD) or a crosslinkable fluoropolymer (PS) having an acid salt type group or a precursor of an acid salt group (PS) Is a fluorine-containing polymer solution (AS) dissolved in an alcohol / water mixed solvent, and the above-mentioned acid salt group is a sulfonic acid group, a carboxyl group, -SO NR ² R ³ , -SO NR ⁴ R ⁵ R ⁶

R ⁷ , -SO M ¹ , one COONR RRR ¹¹ or — COOM ² (R ² is a hydrogen atom or M

Represents ⁵ and R ³ represents an alkyl group or a sulfol-containing group. R ⁴ ,

R ⁹ , R ^1C> and R ¹¹ are the same or different and are each a hydrogen atom or an alkyl group

And M ² And M ⁵ represents an L-valent metal. The L-valent metal is a metal belonging to Group 1, 2, 4, 8, 11, 12, 12, or 13 of the periodic table. ) Wherein the precursor of the acid salt type group is -SO F, -SO NR ²² R ²³ (R ²² and R ²³ are the same or different and represent an alkyl group.)

twenty two

Or a fluorine-containing polymer liquid composition, which is an organic group that is converted to a carboxyl group by hydrolysis.

The present invention is characterized in that a fluorine-containing crosslinked product is produced by applying the above-mentioned fluoropolymer liquid composition to a substrate or impregnating a porous material, followed by removing the liquid medium and performing a crosslinking treatment. This is a method for producing a fluorine-based crosslinked product.

In the present invention, the above-mentioned fluoropolymer liquid composition is applied to a substrate or impregnated in a porous material, then the liquid medium is removed, and a crosslinking treatment is performed using a peroxide conjugate as a crosslinking reaction initiator. A method for producing a fluorinated crosslinked body, which comprises producing a fluorinated crosslinked body. In the latter method for producing a fluorine-containing crosslinked product, the fluorine-containing polymer liquid composition should have a crosslinkable functional group of I or -Br and have a polyfunctional unsaturated compound as a crosslinking agent (B). Can be.

Hereinafter, the present invention will be described in detail.

[0010] The fluoropolymer liquid composition of the present invention also provides a fluoropolymer liquid (A) comprising a liquid medium and a crosslinkable fluoropolymer having a crosslinkable functional group.

The liquid medium is a liquid dispersion medium described below, or a fluorinated solvent or an alcohol Z water mixed solvent.

[0011] The above-mentioned fluoropolymer liquid (A) is a liquid dispersion of particles comprising a crosslinkable fluoropolymer (PD) having an acid salt type group or an organic group which is converted into a carboxyl group by hydrolysis. A fluoropolymer liquid dispersion (AD) dispersed in a solvent or a crosslinkable fluoropolymer (PS) having an acid salt type group or a precursor of an acid salt group (PS) is a fluorine-based solvent. It is a fluoropolymer solution (AS) dissolved in an alcohol / water mixed solvent.

[0012] The acid salt type group is a sulfonic acid group, a carboxyl group or SO NHR ³ (R ³ is

2

Represents a alkyl group or a sulfonyl-containing group. ), Or SO NR ⁴ R ⁵ R ⁶ R ⁷ ,

Three

SO M ¹ , -SO NM ⁵ R ³ , one COONR ⁸ R ⁹ R ¹⁰ R ⁿ or one COOM ² (R ³ is

3 1 / L 2 1 / L 1 / L Same as above. R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ^1G and R ¹¹ are the same or different and are each a hydrogen atom Or an alkyl group, M \ M ² and M ⁵ represents a metal whose valence is L. The L-valent metal is a metal belonging to Group 1, Group 2, Group 4, Group 8, Group 11, Group 12, or Group 13 of the periodic table. ) Is an acid salt type group, and the precursor of the acid salt type group is -SO F, -SO NR ²² R ²³ (R ²² and

twenty two

R ²³ is the same or different and represents an alkyl group. R ²³ is the following, such as -R ²⁸ SO F

2

I know. ) Or an organic group that is converted to a carboxyl group by hydrolysis.

Sulfo in the R ³ - Le containing groups, sulfo - a fluorinated alkyl group having a group, for example, terminal substituent a fluorine-containing alkylsulfonyl group optionally having the like, the fluorine-containing Examples of the alkylsulfur group include, for example, SO R ⁶ Z ² (R ⁶ is

2 f f

Represents a fluorine-containing alkylene group, and z ² represents an organic group. ) And the like. As the organic group, for example, -SO F, -SO H, -SO M 1 can be mentioned, -SO (NR ²⁷ SO R ⁶

2 3 3 1 / L 2 2 f

SO 2) NR ²⁷ SO— (k represents an integer of 1 or more, and R ⁶ represents a fluorine-containing alkylene group.

2 k 2 f

R ²⁷ represents an alkyl group, hydrogen or an L-valent metal. ) Can also be connected indefinitely. Also, —SO (NR ²⁷ SO R ⁶ SO) NR ²⁷ SO F, —SO (NR ²⁷ SO R ⁶ SO) NR ²⁷

2 2 f 2 k 2 2 2 f 2 k

SO X (In each formula, k represents an integer of 1 or more and 100 or less. R ²⁷ and R ⁶ are the same as above. X

3 f

Represents hydrogen or an L-valent metal. ).

[0013] The organic group which is converted into a carboxyl group by hydrolysis is COOR ¹² (R ¹² represents an alkyl group) or CONR ²⁴ R ²⁵ (R ²⁴ and R ²⁵ are the same or different and each is an alkyl group). Represents a group or a hydrogen atom).

Examples of the alkyl group in R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ²² , R ²³ , R ²⁴ , R ²⁵ and R ²⁷ are as described above. And a C1-C4 alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group. Among them, a methyl group or an ethyl group is preferable. As R ²³ , for example, R ²⁸ SO F, —SO (NR ²⁹ SO R ⁶ SO) NR ²⁹ SO— (k is 1 or more

2 2 2 f 2 k 2

Represents an integer, and R ⁶ represents a fluorinated alkylene group. R ²⁸ represents an alkylene group. R ²⁹ f

, Like R ^22, etc., represents an alkyl group. Infinitely connected One they also Yogumata ^{like), -. SO (NR 27} SO R 6 SO) NR 27 SO F (k is 1 or more, 100 represent the following integer R ²⁷及

2 2 f 2 k 2

And R ⁶ are the same as above. ).

f

[0014] The fluoropolymer liquid (A) is composed of a crosslinkable fluoropolymer (PD) having a carboxyl group, an acid salt group, or an organic group that is hydrolyzed to convert to a carboxyl group. It is a fluoropolymer liquid dispersion (AD) or a fluoropolymer solution (AS) composed of a crosslinkable fluoropolymer (PS) having a precursor of a carboxyl group, an acid salt group or an acid-acid salt group. More preferably, it is a fluoropolymer liquid dispersion (AD) comprising a crosslinkable fluoropolymer (PD) having an acid salt type group—SO M ¹ (M ¹

3 1 / L is the same as above. More preferably, it is a fluoropolymer aqueous dispersion (ADA) which also has a cross-linkable fluoropolymer (PD) strength.

[0015] The above-mentioned acid salt type group, a precursor of the acid salt type group, and an organic group which is converted into a carboxyl group by hydrolysis are represented by the following general formula (I)

-0- (CF CFY ¹ — O)-(CFY ² ) (I)

2 n m

(In the formula, Y ¹ represents a fluorine atom, a chlorine atom or a perfluoroalkyl group. N represents an integer of 0 to 3. The n number of Y ¹ may be the same or different. Y ² represents a fluorine atom or a chlorine atom, m represents an integer of 115. m Y ² may be the same or different! ), Which is bonded to a fluoroether side chain represented by the following formula: wherein the fluoroether side chain constitutes a perfluoroethylene unit in the main chain of the crosslinkable fluoropolymer, and is etherified to a carbon atom. It is preferable that they are combined. The perfluoroalkyl group is preferably a group having 13 to 13 carbon atoms.

The crosslinkable fluorine-containing polymer has the following general formula (II)

CF = CF-0- (CF CFY ¹ — O)-(CFY ² ) —A (II)

2 2 n m

(Wherein, Y ¹ represents a fluorine atom, a chlorine atom or a perfluoroalkyl group. Η represents an integer of 0 to 3. η 個¹ may be the same or different. Υ ² represents a fluorine atom or a chlorine atom, m represents an integer of 1 to 5. m Y ² may be the same or different! A, —SO X

2, -COOM ³ or hydrolyzed carb

1 / L

Represents an organic group converted to a xyl group. X is a halogen atom, -OM ⁴

1 / L, -NR ¹³ R ^14, or ^{^{^{^{ONR 15 R 16 R 17 R 18}}}} (R 13 and R ¹⁴ are the same or different, a hydrogen atom, an alkali metal, an alkyl group or sulfo -. Represents a Le-containing group M ³ and M ⁴ represents an L-valent ^{^{^{metal. R 1 5, R 16,}}} R 17 and R ¹⁸ are the same or different, represented by a representative.) a hydrogen atom or an alkyl Le group having a carbon number of 1 one 4 Or a fluorine-containing polymer precursor obtained by polymerizing a fluorofluoroether derivative or a fluorine-containing polymer precursor derived from the above fluorine-containing polymer precursor. preferable.

When the crosslinkable fluorine-containing polymer is a fluorine-containing polymer precursor, in the above general formula (Π), —SO X (X is -OM ⁴ NR ¹³ R ¹⁴ or ONR ¹⁵ R ¹⁶ R ¹⁷ R ¹⁸ ; ⁴ is

2 1 / L

Same as above. R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ are the same as above (provided that -SO X is an acid-

A substance that corresponds to a diacid salt group. ) o) and COOM ³ are the crosslinkable fluorine-containing

1 / L

It is the same as the acid / acid salt type group in the polymer.

The above “derived from the fluoropolymer precursor” is obtained by hydrolyzing the fluoropolymer precursor in the presence of water as described below, or the above-mentioned general formula of the fluoropolymer precursor. The alkali metal as M ³ or M ⁴ in (Π), or the alkali metal as R ¹³ and Z or R ¹⁴ or the L-valent metal in the sulfol-containing group may be exchanged for another metal or other cation. It was done.

In the above fluorovinyl ether derivative, n in the above general formula (Π) represents an integer of 0 to 3. N is preferably 0 or 1. M in the above general formula (Π) represents an integer of 115. The above m is preferably 2.

In the above general formula (Π), Y ¹ represents a fluorine atom, a chlorine atom or a perfluoroalkyl group, and the n Y ^{1 s} may be the same or different. The above perfluoroalkyl group is not particularly limited, and examples thereof include a perfluoroalkyl group having 13 to 13 carbon atoms such as a trifluoromethyl group and a pentafluoroethyl group.

Y ² in the above general formula (Π) preferably represents a fluorine atom or a chlorine atom, and the m Y ^{2 s} may be the same or different. In the above general formula (Π), Y ¹ is preferably a trifluoromethyl group, and γ ² is more preferably a fluorine atom

The fluorofluoroether derivative is a Y ¹ force trifluoromethyl group in the above general formula (Π), Y ² is a fluorine atom, n force is 0 or 1, and m force is 2. Is even more preferred.

[0020] The fluoropolymer precursor is preferably a binary or higher copolymer obtained by polymerizing the above-mentioned fluorobutyl ether derivative and a fluoroethylenic monomer. When the fluoropolymer precursor is a copolymer of two or more of the above, The composition ratio of the fluoroether derivative to the fluorine-containing ethylenic monomer is preferably from 1:99 to 50:50, more preferably from 5:95 to 30: 70! /.

The fluorine-containing ethylenic monomer is not particularly limited as long as it has a vinyl group, and is different from the above fluorovinyl ether derivative.

Examples of the fluorine-containing ethylenic monomer include, for example, the following general formula

CF = CF-Rf ¹

2

(In the formula, Rf ¹ represents a fluorine atom, a chlorine atom, Rf ² or ORf ² , and Rf ² has an ether oxygen having 19 to 19 carbon atoms, and may have a straight-chain or branched chain. A haloethylenic monomer represented by the following general formula:

CHY ³ = CFY ⁴

(In the formula, Y ³ represents a hydrogen atom or a fluorine atom, Y ⁴ represents a hydrogen atom, a fluorine atom, a chlorine atom, Rf ³ or ORf ^3. Rf ³ represents an ether oxygen having 19 to 19 carbon atoms. And represents a linear or branched fluoroalkyl group.), And a hydrogen-containing fluoroethylenic monomer represented by the following formula:

[0022] The fluorine-containing ethylenic monomer is CF = CF, CH = CF

2 2 2 2, CF = CFC1

2, CF =

2

CFH, CH = CFH, CF = CFCF, and CF = CF—O—Rf ⁴ (where Rf ⁴ is carbon

2 2 3 2

It represents a fluoroalkyl group having the number of 119 or a fluoropolyether group having the number of 119. ) Is preferably at least one selected from the group consisting of fluorobutyl ethers. The above-mentioned fluorobutyl ether is preferably a perfluoroalkyl group having Rf ⁴ of 13 to 13 carbon atoms! /.

The fluorine-containing ethylenic monomer is more preferably a perhaloethylenic monomer, particularly preferably a perfluoroethylenic monomer, and more preferably CF = CF. Including the above

twenty two

As the fluorinated ethylenic monomer, one or more kinds can be used.

The crosslinkable fluoropolymer can be polymerized by a conventionally known polymerization method such as solution polymerization, emulsion polymerization and suspension polymerization.

The crosslinkable fluoropolymer may be a seed polymer.

[0024] When the crosslinkable fluoropolymer has a sulfonic acid group or a carboxyl group, or a salt of the sulfonic acid group or the carboxyl group, the fluorine-containing polymer is So x ¹ ^ ¹ of the limmer precursor represents a halogen atom. ) Or coz ^ z ¹ is

2

Represents an alkoxyl group. ) Is preferably obtained by hydrolyzing) in the presence of water.

Examples of the alkoxyl group in COZ ¹ include an alkoxyl group having 114 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Among them, a methoxy group or an ethoxy group is preferable.

[0025] The hydrolysis is performed by adding an alkali, preferably an aqueous alkali solution. Examples of the alkali include alkalis that may be used for hydrolysis.Examples include alkali metal or alkaline earth metal hydroxides and carbonates. Examples of the hydroxide include: Examples include sodium hydroxide, potassium hydroxide, lithium hydroxide, and the like. Examples of the carbonate include sodium carbonate, sodium hydrogen carbonate, and the like.

The hydrolysis is usually carried out at a normal temperature of 130 ° C. for 1 minute to 10 hours. For example, when the precursor of the acid-acid salt type group of the fluoropolymer precursor is SOF,

In general, it is generally carried out at 80 ° C-100 ° C for 10 minutes and 5 hours.

[0026] The crosslinkable fluoropolymer has a crosslinkable functional group.

The crosslinkable functional group is a group consumed in a crosslinking reaction. The above “crosslinking” is to form a crosslinking bond. Examples of the above-mentioned crosslinkable functional group include, in addition to the above-mentioned acid-acid salt type group and precursor of the acid-acid salt type group, an odo group [-1], a bromo group [-Br], a cyano group, and a cross-linkable carboxy group. Examples include a sil group, a cyanato group, a hydroxyl group, a perfluorovinyl group, a carbonyl group and a carbonyl group.

The above-mentioned acid salt-type groups, organic groups that are converted to carboxyl groups by hydrolysis, and precursors of acid salt-type groups include functional groups of a type that can be consumed in the crosslinking reaction. In the specification, a functional group of a kind that can be consumed in a crosslinking reaction, and a group consumed in the crosslinking reaction is the above-mentioned crosslinkable functional group! /, And a functional group is not consumed in the crosslinking reaction! It is referred to as an acid-acid salt type group, an organic group capable of being converted to a carboxyl group by hydrolysis, and a precursor of an acid salt-type group (hereinafter sometimes referred to as a "non-crosslinkable functional group"). Examples of the type of functional group that can be consumed in the crosslinking reaction include a carboxyl group and the like.

In the present specification, the “crosslinkable carboxyl group” refers to a carbohydrate consumed in a crosslinking reaction. Since it is a xyl group, it should be conceptually distinguished from the carboxyl group which is not consumed in the crosslinking reaction and remains as the above-mentioned acid group even after the crosslinking treatment described later. When the crosslinkable fluoropolymer in the present invention has both a carboxyl group as an acid group and the above-mentioned crosslinkable carboxyl group, usually both carboxyl groups are present in total in excess with respect to the crosslinking agent (B). Carboxyl groups not consumed in the crosslinking reaction remain even by the crosslinking treatment, and the remaining carboxyl groups can function as the above-mentioned acid groups. In the present specification, the carboxyl group consumed in the crosslinking reaction is the above-mentioned crosslinkable carboxyl group, and the carboxyl group remaining without being consumed in the crosslinking reaction is a carboxyl group as an acid group.

The crosslinkable fluoropolymer depends on the crosslinking reaction conditions and the like, but preferably has an equivalent weight [EW] of 300 to 5000 after the crosslinking reaction. A more preferred lower limit of EW after the crosslinking reaction is 500, and a more preferred upper limit is 1500. In this specification, the equivalent weight [EW] after the above-mentioned crosslinking reaction represents the amount of the above-mentioned non-crosslinkable functional group, and does not represent the amount of the crosslinkable functional group.

The crosslinkable fluoropolymer is preferably used as a resin instead of a rubber after the crosslinking reaction.

The fluoropolymer liquid composition of the present invention is composed of the fluoropolymer liquid (A) and the crosslinking agent (B), depending on the type of the crosslinkable functional group and the crosslinking system used. Is preferred.

The cross-linking agent (B) can be cross-linked without using the cross-linking agent (B), for example, when the cross-linkable functional group is a cross-linkable carboxyl group, a cyano group, 1 I, 1 Br, or the like. is there. For example, when the crosslinkable functional group is I or Br, crosslinking can be performed without using the crosslinking agent (B), but crosslinking may be performed using the crosslinking agent (B).

Examples of the crosslinking agent (B) include those capable of reacting with a carboxyl group, an alkoxycarbol group or a cyano group, particularly those used in oxazole crosslinking systems, imidazole crosslinking systems, and thiazole crosslinking systems. The crosslinking agent (B) used in the oxazole cross-linking system, imidazole cross-linking system, and thiazole cross-linking system is, for example, the following general formula (IV) [0028] [Formula 1]

(In the formula, one of R 1 and R 2 represents -NH, and the other represents -NH

22 -NH-Ph, -OH or

— Indicates SH. Ph represents a phenyl group. R ²¹ is —SO—O CO—, carbon number 1

2 one

6 represents an alkylene group, a perfluoroalkylene group having 1 to 10 carbon atoms, or a single bond. )), A bisdiaminophenol-based crosslinking agent, a bisaminophenol-based crosslinking agent, a bisaminothiophenol-based crosslinking agent represented by the following general formula (V):

[0030] [Formula 2]

(Where R ¹ is the same as above, R ^b is

[0032] [Formula 3]

[0033] or

[0034] [Formula 4]

Represents the following. ) Represented by the following general formula (VI) or the following general formula (V II): [0036] [Formula 5]

(In the formula, R represents a perfluoroalkylene group having 11 to 10 carbon atoms.)

f

[0038] [Formula 6]

(Wherein p represents an integer of 110), and a bisamidoxime-based crosslinking agent represented by the formula: These bisaminophenol-based crosslinking agents, bisaminothiophenol-based crosslinking agents, bisdiaminophenyl-based crosslinking agents, etc. are conventionally used in crosslinking systems having a tolyl group as a crosslinking point. Reacts with a carboxyl group and an alkoxycarbol group of the compound to form an oxazole ring, a thiazole ring, and an imidazole ring to give a crosslinked product.

As the crosslinking agent (B), a compound having a plurality of 3-amino-4-hydroxyphenyl groups and Z or 3-amino-4 mercaptophenyl groups, or the following general formula (ΠΙ): [Formula 7]

[0041] (wherein, R, R ^u and R ¹ are as defined above.) Represented by the crosslinking agent (B1), for example, 2, 2-bis (3-amino-4-hydroxy Hue - Le) to Xafluoropropane (generic name: bis (aminophenol) AF), 2,2 bis (3 amino-4 mercaptophenol) hexafluoropropane, tetraaminobenzene, bis 3,4-diaminopheninolemethane, bis 3, 4-diaminophenol and 2,2 bis (3,4-diaminophenol) hexafluoropropane. [0042] Examples of the crosslinking agent (B) include a polyamine compound, a polyisocyanate, and a polyepoxy compound. Examples of the polyamined conjugate include polyamines such as hemisamethylenediamine, triethylenetetramine, and triethylenediamine; and combinations of polyamine salts and guandinine derivatives. Examples of the above polyisocyanate-to-animate conjugate include tolylene diisocyanate, diphenolemethanediisocyanate, hexamethylene diisocyanate and the like. The polyisocyanate-to-animal conjugate may be of a block type in which a prepolymer or a curing temperature can be selected. Examples of the cross-linking agent (B) include a combination of an epoxy conjugate and a quaternary ammonium salt, a quaternary phosphonium salt or a basic conjugate.

When the crosslinkable functional group is a cyano group or a crosslinkable carboxy group, the crosslinker (B) may be the crosslinker (B1) represented by the general formula (ΠΙ). Like,.

[0044] In the above general formula (III), R ¹⁹ and R ² are a force that is both NH, or one is N

2

H and the other is preferably NH—Ph.

2

[0045] When the crosslinkable functional group is -1 or -Br, the crosslinking agent (B) is preferably a polyfunctional unsaturated compound.

[0046] The polyfunctional unsaturated compound may be any compound having a reaction activity with respect to a polymer radical originating from iodine atom and Z or bromine atom generated by heating or decomposition of a peroxide compound described later. The type is not particularly limited. Preferred polyfunctional unsaturated compounds include, for example, various diatalates, trimethylolpropane triatalylate HTMTPA), trimethylolpropane trimethatalylate, triallyl isocyanurate (TAIC), triaryl cyanurate, triallyl trimellitate , Pentaerythritol triatalylate, pentaerythritol tetraatalylate, dipentaerythritol hexaatalate, N, N'-m phenylene bismaleimide, dipropargyl terephthalate, diaryl phthalate, tetraaryl terephthalamide, triallyl phosphate, etc. Is mentioned. Among them, those having three or more crosslinkable functional groups per molecule are more preferably triallyl isocyanurate, which is preferable from the viewpoint of easy crosslinking of the crosslinkable fluorine-containing polymer.

[0047] The amount of the polyfunctional unsaturated compound to be used is about 0.05 to 10 parts by mass with respect to 100 parts by mass of the crosslinkable fluoropolymer, and a preferable lower limit is 0.5 part by mass, and a preferable upper limit is 0.5 parts by mass. The limit is 5 parts by weight.

[0048] The cross-linking agent (B) may be used in any of the fluoropolymer liquid composition (AS) and the fluoropolymer liquid dispersion (AD) described below for the fluoropolymer liquid composition of the present invention. The content is preferably 0.05 to 20% by mass of the solid content of the fluoropolymer liquid composition of the present invention, and more preferably 0.1% by mass or more.

The solid content of the fluoropolymer liquid composition is preferably 0.5 to 50 parts by mass with respect to 100 parts by mass of the fluoropolymer liquid composition.

[0049] The fluoropolymer liquid composition of the present invention comprises a fluoropolymer liquid (A) and at least one alcohol selected from the group consisting of methanol, ethanol, propanol and tetrafluoropropanol (A). It is preferable that it comprises C).

The alcohol (C) is more preferably 2,2,3,3-tetrafluoropropanol, which is more preferably tetrafluoropropanol. As the alcohol (C), only one kind may be used, or two or more kinds may be used.

The alcohol content of the alcohol (C) is preferably 10 to 80% by volume of the fluoropolymer solution (A). By adding the alcohol (C) in an amount within the above range, the surface tension of the fluoropolymer liquid composition of the present invention can be adjusted, and a film described below is prepared using the fluoropolymer liquid composition of the present invention. When forming, a homogeneous film can be obtained. The fluoropolymer liquid composition may be composed of the fluoropolymer liquid (A), the alcohol (C), and the above-mentioned crosslinking agent (B).

[0051] The fluoropolymer liquid composition of the present invention is preferably composed of a fluoropolymer liquid (A) and further a film-forming aid (D). By adding the film-forming auxiliary (D), the film-forming property is remarkably improved, and the production of a thin film by the casting method becomes easy.

[0052] The film-forming auxiliary (D) is preferably an organic liquid that is compatible with water and has a boiling point of more than 100 ° C and not more than 300 ° C. If the temperature is below 100 ° C, the boiling point is usually the same as or lower than that of water, so that particles having a crosslinkable fluoropolymer (PD) force are dispersed in an aqueous dispersion medium! When a fluoropolymer liquid dispersion (AD) is obtained by mixing water (ADA) with a film-forming auxiliary (D) and then evaporating water (organosol), the film-forming auxiliary (D) remains. It is not possible to remove the aqueous dispersion medium while performing the process. 300 ° C If it exceeds, when it is necessary to remove the film-forming auxiliary (D) from the film formed using the obtained fluoropolymer liquid composition, the removal tends to be difficult. A preferred lower limit of the boiling point of the film-forming auxiliary (D) is 150 ° C, and a preferred upper limit is 250 ° C.

The film-forming auxiliary (D) includes the fluoropolymer liquid (A) of the present invention, the fluoropolymer aqueous dispersion (ADA), or the crosslinkable fluoropolymer dissolved in an alcohol Z water mixed solvent. When it is a fluoropolymer solution (AS), it is particularly preferable to use it.

[0053] The above film-forming auxiliary (D), the precursor of the acid 'salt groups is SO NR ^²² R ²³ (R ²² and R ²³

2

Is the same as above. ) Or an organic group that is converted to a carboxyl group by hydrolysis when the crosslinkable fluoropolymer (PS) in the fluoropolymer liquid (A) in the present invention has —SOF This crosslinkable fluoropolymer (PS) dissolves in fluorinated solvents.

2

Excluding the fluoropolymer solution (AS), but (1) phosphate ester, (2) monohydroxy ether of ethylene oxide oligomer, and Z or (3) cyclic amide or cyclic Preferably, it is an amide derivative.

[0054] The film-forming auxiliary (D) is preferably one in which 0.1 to 100 parts by mass is blended with respect to 1 part by mass of the crosslinkable fluoropolymer. When the amount is less than 0.1 part by mass, when a film is formed using the obtained fluorine-containing polymer liquid composition, the film-forming property may be insufficient. If the amount is more than 100 parts by mass, it is not economically preferable to obtain an effect commensurate with the compounding amount. A more preferred lower limit is 0.5 parts by mass, and a more preferred upper limit is 20 parts by mass. The fluoropolymer liquid composition comprises the fluoropolymer liquid (A) and the film-forming auxiliary (D). And the cross-linking agent (B) described above, or the fluorine-containing polymer liquid (A), the cross-linking agent (B), and a film-forming auxiliary (D) and an alcohol ( C).

[0055] The above-mentioned fluoropolymer liquid composition may be a composition that can act as the fluoropolymer liquid (A) and further with the active substance (E)! /.

Examples of the active substance (E) include a catalyst and the like which will be described later for the method for producing a fluorine-containing crosslinked product of the present invention.

The fluoropolymer liquid composition comprises a fluoropolymer liquid (A), an active substance (E), It may be at least one selected from the group consisting of a bridging agent (B), an alcohol (C) and a film-forming auxiliary (D)! /.

The fluoropolymer liquid (A) is preferably a fluoropolymer liquid dispersion (AD). The solid content of the fluoropolymer liquid dispersion (AD) is preferably 2 to 80% by mass. It is preferred that As described above, when the fluoropolymer liquid composition of the present invention is composed of the fluoropolymer liquid dispersion (AD) and the crosslinker (B), the crosslinker (B) is used. It is preferably 0.1 to 20% by mass of the solid content of the composition.

[0057] The fluoropolymer liquid dispersion (AD) is preferably an aqueous fluoropolymer dispersion (ADA) in which the liquid dispersion medium is an aqueous dispersion medium. Is preferably 10 to 100% by mass. If the water content of the aqueous dispersion medium is less than 10% by mass, dispersibility tends to deteriorate, which is not preferable. A more preferred lower limit is 40% by mass.

[0058] In the present specification, the "aqueous dispersion medium" is a dispersion medium of a crosslinkable fluoropolymer (PD) and contains water. As the aqueous dispersion medium, any water-soluble organic solvent may be used as long as it is water-based. The aqueous dispersion medium may have additives such as a surfactant and a stabilizer usually used for an aqueous dispersion.

When the crosslinkable fluoropolymer has an acid-acid salt group, the aqueous dispersion of the fluoropolymer (ADA) has sufficient dispersion stability even if it does not substantially contain a surfactant. It has the property.

[0059] When the crosslinkable fluoropolymer is obtained by emulsion polymerization, the fluoropolymer aqueous dispersion (ADA) may be the dispersion itself after polymerization, or may be included in the dispersion after polymerization. When the crosslinkable fluorine-containing polymer is a fluorine-containing polymer precursor having an acid-acid salt type group precursor, it may be one obtained through the above-mentioned hydrolysis.

[0060] The aqueous fluoropolymer dispersion (ADA) is preferably purified for the purpose of removing inorganic salts, low molecular weight impurities, ultra-low molecular weight polymers, and the like. Examples of the purification method include ultrafiltration.

[0061] The fluoropolymer liquid dispersion (AD) is an aqueous dispersion of the fluoropolymer aqueous dispersion (AD). A loose organosol obtained by the method of evaporating water after blending a film-forming auxiliary (D) with A)!

[0062] The fluoropolymer liquid (A) may be a fluoropolymer solution (AS). The crosslinkable fluoropolymer (PS) may be 0.1 to 10 of a fluoropolymer liquid composition. It is preferable that the content be in mass%. As described above, when the fluoropolymer liquid composition of the present invention comprises the fluoropolymer liquid dispersion (AS) and the crosslinking agent (B), the crosslinking agent (B) is It is preferably 0.1 to 20% by mass of the solid content of the polymer liquid composition. The liquid medium obtained by dissolving the crosslinkable polymer (PS) in the fluoropolymer solution (AS) is a crosslinkable fluoropolymer (PS) having a precursor of an acid salt type group. In some cases, it is preferable to use a mixed solvent of alcohol and water when the compound has an acid salt type group, which is preferably a fluorine-based solvent.

[0063] The fluorine-based solvent has a fluorine atom in the molecule and has a boiling point of 30 to 150 ° C. The above-mentioned fluorine-based solvent may be any of aromatic and aliphatic as long as it has a fluorine atom in the molecule and has a boiling point of 30 to 150 ° C.

The fluorine-based solvent is not particularly limited, and includes, for example, chlorofluorocarbon, perfluorobenzene, and the like. Among them, the following general formula (VIII)

C H C1 F (VIII)

a b c (2a + 2-b-c)

(In the formula, a is an integer of 3-6, b is an integer of 0-2, and c is an integer of 0-4.) The following general formula (IX)

C H C1 F (IX)

a b c (2a— b— c)

(In the formula, a, b and c are the same as described above.)

[0064] The above-mentioned fluorinated fluorocarbon is preferably those in which the b force O or 1, c in the above general formulas (VIII) and (IX) is 1 or 2, CF

3 3 2

Mixture with CC1FCF CF, Mixture with CF CF CHC1 and CC1F CF CHC1F [: HCF

2 3 3 2 2 2 2

C-225] or H (CFCF) CI.

2 2 2

Perfluorocyclobutane can also be used as the above-mentioned fluorofluorocarbon. [0065] Examples of the alcohol used in the alcohol Z water mixed solvent include methanol, ethanol, and isopropyl alcohol.

The mixing ratio of alcohol in the alcohol Z water mixed solvent, 10: 90- 9 0: 10 (alcohol: water, volume ^_0/0) it is preferably a! /.

The alcohol used in the alcohol / water mixed solvent can be the same as the alcohol (C) for improving the film-forming property described above. It is essential because it is essential for dissolving the crosslinkable fluoropolymer (PS). This is a concept that should be distinguished from non-alcohol (C).

[0066] The dissolving treatment of the crosslinkable fluoropolymer (PS) in the fluoropolymer solution (AS) is performed at a boiling point of the fluorine-based solvent or the alcohol-Z water mixed solvent or higher, preferably 120 ° C or higher, more preferably It is performed at 150 ° C or higher. Therefore, the dissolution treatment is preferably performed in a pressure vessel. The time of the dissolution treatment depends on the temperature of the dissolution treatment, but is usually 10 minutes to 300 hours.

The above boiling point and the temperature of the dissolution treatment are values at normal temperature and normal pressure. In the present specification, the above “normal temperature” is a normal temperature in a normal sense, and is usually 20 to 30 ° C. In the present specification, the above “normal pressure” is normal pressure in a normal meaning, and is usually 1013 hectopascals (= latm).

[0067] In the fluoropolymer liquid composition of the present invention, the liquid temperature was returned to-and normal temperature when heated to produce the fluoropolymer liquid dispersion (AD) or the fluoropolymer solution (AS). It can be prepared by adding a crosslinking agent (B) later. By preparing the fluoropolymer liquid composition of the present invention by such a procedure, if the crosslinking agent (B) is added during the heating, the crosslinking reaction proceeds, and the desired fluoropolymer liquid composition is obtained. The problem of not being able to obtain is not caused.

[0068] The fluoropolymer liquid composition of the present invention can be suitably used as a proton conductive material, particularly, a material for a proton conductive membrane.

[0069] The process for producing a fluorine-containing crosslinked product of the present invention comprises applying the fluoropolymer liquid composition of the present invention to a substrate or impregnating a porous material, followed by removing the liquid medium and performing a crosslinking treatment. This is for producing a system crosslinked product. The fluorinated crosslinked product has a higher mechanical property than a film obtained without applying the fluorinated polymer liquid composition to a substrate or impregnating a porous material with a liquid medium and then performing a crosslinking treatment. Thus, the dimensional change due to the amount of moisture can be reduced, and as a result, the durability can be improved.

The method for producing a fluorinated crosslinked product of the present invention is generally capable of industrially efficiently and stably producing a fluorinated crosslinked product by using the fluoropolymer liquid composition of the present invention. .

[0070] The substrate is not particularly limited, and includes, for example, the above-described porous support, resin molded body, metal plate, and the like, and an electrolyte membrane, a porous carbon electrode, and the like used for a fuel cell or the like are preferable. .

The porous material may be any of organic and inorganic materials as long as it has a porous structure. For example, glass wool, ceramic, alumina, polytetrafluoroethylene resin, polytetrafluoroethylene molding Body stretched porous film, carbon, and various types of polymers.

[0071] The liquid solvent can be usually removed by drying at normal temperature and under Z or heating. A film obtained by applying the above-mentioned fluoropolymer liquid composition to a substrate or impregnating a porous material into a film can be easily dissolved in water or the like if the above-mentioned drying is performed only at room temperature. It is preferable to perform drying under. The “under heating” in the removal of the liquid medium is usually 80 to 400 ° C., preferably 200 ° C. or more.

[0072] The above-mentioned fluorine-containing crosslinked product may contain a substrate or a porous material. However, when it is applied to a substrate, it is peeled off from the surface of the substrate by immersion in water or the like. Alternatively, it can be obtained as a thin film containing no base material.

[0073] The crosslinking treatment is preferably a crosslinking treatment using high energy.

The cross-linking treatment using high energy is performed by heating, although it is preferable to perform heating, radiation irradiation, electron beam irradiation, or light irradiation, in terms of the availability of equipment and ease of handling. Is more preferable.

The heating in the above crosslinking treatment is usually performed in an oven or a pressurizer at 100 to 400 ° C. for 1 minute to 10 hours. [0074] When a peroxide compound described below is used as a crosslinking reaction initiator, the crosslinking treatment is more preferably performed in a nitrogen atmosphere, which is preferably performed substantially in the absence of oxygen. In the presence of oxygen, radicals generated by cleavage of the peroxide compound are likely to be trapped by oxygen and hinder the progress of crosslinking.

[0075] The method for producing a fluorinated crosslinked product of the present invention also comprises a step of applying the above-mentioned fluorinated polymer liquid composition of the present invention to a substrate or impregnating a porous material, and then removing the liquid medium to start a crosslinking reaction. A fluorine-containing crosslinked product may be produced by performing a crosslinking treatment using a peroxide compound as an agent.

When performing the crosslinking treatment using a peroxide conjugate as a crosslinking reaction initiator, the fluorine-containing polymer liquid composition has a crosslinking functional group of -1 or -Br, and a polyfunctional crosslinking agent (B). Those using unsaturated compounds are preferred. As the polyfunctional unsaturated compound, triallyl isocyanate is preferred!

[0076] The peroxide compound may have an appropriate decomposition rate at a temperature higher than the boiling point of the liquid medium and lower than the decomposition temperature of the crosslinkable fluoropolymer, and may have an evaporation temperature that does not readily evaporate. Preferred such compounds include, for example, di-t-butyl peroxyalkanes such as 2,5 dimethyl-2,5-di (t-butylperoxy) hexane.

[0077] The mixing amount of the peroxide compound is preferably 0.001 to 15 parts by mass with respect to 100 parts by mass of the fluoropolymer. If the amount is less than 0.001 part by mass relative to 100 parts by mass of the fluoropolymer, the crosslinking reaction may be insufficient. If the amount exceeds 5 parts by mass with respect to 100 parts by mass of the fluoropolymer, the amount of peroxide residue increases and the strength may decrease. The more preferable lower limit of the amount of the peroxide compound is 0.01 part by mass and the more preferable upper limit is 1 part by mass with respect to 100 parts by mass of the fluoropolymer.

[0078] It is preferable that the coating or impregnation is performed at a relatively low temperature and then the temperature is raised to perform a crosslinking treatment. The application or impregnation may be repeated alternately with the crosslinking treatment.

[0079] The above-mentioned fluorine-based crosslinked product is not particularly limited, but can be used, for example, as proton conductivity, particularly as an electrolyte membrane, an ion exchange membrane, or the like. When the above-mentioned fluorine-based crosslinked product is used as an electrolyte membrane or the like, the film thickness can be 5 to 200 m. A preferable lower limit of the film thickness is 10 / zm, and a preferable upper limit of the film thickness is 50 μm.

When the above-mentioned fluorine-containing crosslinked product is used as an electrolyte membrane or the like, the membrane expansion rate is low even after being impregnated for a long time. For example, a crosslinkable polymer having 18 mol% of perfluoro (ethylvinyl ether) sulfol chloride unit is provided. Even when the fluorine-containing crosslinked product obtained by crosslinking the fluorine-containing polymer is impregnated with an aqueous medium for about 15 hours, the film expansion coefficient is usually 10% by volume or less before the impregnation. The above-mentioned fluorine-containing crosslinked body is not particularly limited, and examples thereof include an electrolyte membrane of a polymer electrolyte fuel cell, a membrane for a lithium battery, a membrane for salt electrolysis, a membrane for water electrolysis, a membrane for hydrohalic acid electrolysis, and an oxygen concentrator. It can be used for membranes for instruments, membranes for humidity sensors, membranes for gas sensors, etc.

[0080] The fluorine-containing crosslinked product obtained by the method for producing a fluorine-containing crosslinked product of the present invention may include an active substance-fixed crosslinked substance containing the active substance (E).

[0081] The active substance (E) is not particularly limited as long as it has an activity in the active substance-fixed crosslinked body, and may be selected according to the purpose of the active substance-fixed crosslinked body of the present invention. Force appropriately selected For example, a catalyst can be suitably used.

[0082] The catalyst is not particularly limited as long as it is a catalyst usually used as an electrode catalyst. For example, a metal containing platinum, ruthenium, or the like; Examples of the complex include an organometallic complex in which at least one of its central metals is platinum or ruthenium. The metal containing platinum, ruthenium, etc. may be a ruthenium-containing metal, for example, ruthenium alone, but the platinum-containing metal, which is preferably a platinum-containing metal, is not particularly limited. For example, a simple substance of platinum (platinum black); a platinum-ruthenium alloy; The above catalyst is usually used by being supported on a carrier such as silica, alumina and carbon.

[0083] The active substance-fixed crosslinked body usually contains a component such as an electrode constituting a solid polymer electrolyte fuel cell, and may be an electrode body for a solid polymer electrolyte fuel cell. preferable.

[0084] In the above-mentioned fluorine-containing crosslinked product, the electrode assembly for a solid polymer electrolyte fuel cell is in contact with the electrolyte membrane. It can be used as a combined membrane-electrode assembly (MEA).

The invention's effect

[0085] Since the fluoropolymer liquid composition of the present invention has the above-described constitution, it is possible to industrially efficiently and stably produce a crosslinked body having excellent mechanical properties and durability and having a small dimensional change due to water content. it can.

BEST MODE FOR CARRYING OUT THE INVENTION

[0086] Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples.

Example 1

In a SUS autoclave with an internal volume of 500 ml, 227.5 g of perfluorocyclobutane as a solvent, perfluoro (ethyl ether) sulfol fluoride (PFSF, CF =

2

CFOCF CF SO F) 168.2 g CF = CFOCF CF (CF) OCF CF CN (CNV

2 2 2 2 2 3 2 2

E) was charged with 16.lg and degassed. While stirring at 800 rpm, at a temperature of 30 ° C., tetrafluoroethylene [TFE] was injected to a total pressure of 0.33 MPa, and the initiator di (ω-hydroperoxide hexanoyl) peroxide was introduced. 8 weight ^_0/0 hexanes Pafuruo port solution 3. began pressed the polymerization reaction 56 g. During the reaction, TFE was introduced from outside the system to keep the pressure constant, and PFSF consumed in the reaction was intermittently injected with a total of 7. Og. Two hours later, unreacted TFE was discharged out of the system, and the polymerization reaction was stopped. The stirring state in the system was good. After the completion of the polymerization reaction, 250 ml of black form was charged, and the mixture was stirred for 30 minutes. Next, the mixture was subjected to solid-liquid separation using a centrifugal separator, and 250 ml of black-mouthed form was added to the solid content, followed by stirring for 30 minutes. This operation was performed three times to wash the polymer. Next, the remaining polymer was removed from the washed polymer under a vacuum of 120 ° C. to obtain 21.8 g of a copolymer a. The content of PFSF estimated from 300 ° C. melt NMR of the obtained copolymer a was 16.2 mol%, and the content of CNVE was 1.1 mol%.

[0088] 400 ml of H (CF) CI as a fluorine-based solvent was added to 4 g of the obtained copolymer a, and the volume was 60

twenty four

Introduced into Oml SUS pressure vessel. After keeping it at 150 ° C for 12 hours, it was taken out to obtain a colorless and transparent solution. The resulting solution contains journals, polymers, and science polymers. 2, 2-bis [3-amino-4- (N-phenylamino) phenol, a crosslinking agent synthesized by the method described in I. Chemistry, Vol. 20, pp. 2381-2393 (1982). 32 mg of hexafluorop mouth bread (AFTA-Ph) was mixed. The resulting solution is impregnated with a polytetrafluoroethylene [PTFE] porous membrane (manufactured by Daikin Industries, Ltd.), air-dried for 30 minutes, and then dried in an oven set at 80-100 ° C for 30 minutes to obtain a coating film. Formed. After that, baking was performed at 200 ° C for 10 minutes, and the film was immersed in pure water to peel off the glass sheet thin film. The obtained thin film has a thickness of 15 μm.

Example 2

In a 300 ml ice-cooled stirred autoclave, 150 ml of pure water, 3 g of perfluoroammonium octanoate, perfluoro (ethylcarbyl ether) sulfofluoride (PFSF, CF = CFOCF CF SO F) 37 g, I ( CF) I 0.18g, persulfate ammo

2 2 2 2 2 4

After adding 60 mg of P.I.m. and sufficiently replacing the internal space with tetrafluoroethylene [TFE], pressurize to 0.2 MPa with TFE, immediately raise the temperature in the system to 60 ° C, and add TFE. The polymerization was started with the pressure supplied to the reactor at 0.8 MPa. As the pressure drops, additional TFE is supplied to keep the pressure at 0.8-0.75MPa, and the reaction is continued.After 6 hours, the reaction is quenched to 20 ° C or less, and the unreacted TFE is released to stop the polymerization. did. 240 g of a slightly turbid transparent aqueous fluoropolymer dispersion was obtained.

A part of the obtained aqueous fluoropolymer dispersion (BDA-1) is coagulated with nitric acid, washed with water and dried, and the crosslinkable fluoropolymer obtained has an iodine content of 0.1% and 300 ° C. C melting NM R force The estimated PFSF content is 18.5 mol ⁰ /. Met.

50 ml of the obtained fluoropolymer aqueous dispersion was diluted twice with pure water, stirred in a 200 ml beaker, the temperature was set to 55 ° C, and a 10 mass% aqueous potassium hydroxide solution was added dropwise. While maintaining the pH at 10 or more, the fluoropolymer precursor has

2 Hydrolysis was performed. After about 3 hours, no decrease in pH was observed, but the hydrolysis was continued for another 2 hours and stopped. During this time, precipitation of the fluoropolymer was not visually confirmed. The resulting reaction solution was subjected to centrifugal ultrafiltration to remove low molecular substances and to purify and concentrate the fluoropolymer using Centriprep YM-10 (manufactured by Amicon). The resulting fluoropolymer dispersion had a fluoropolymer concentration of 32% by mass. Obtained While stirring 10 ml of the aqueous fluoropolymer dispersion, 12 ml of triethyl phosphate and 5 ml of isopropanol, 50 mg of Perhexa 25B (manufactured by NOF Corporation), and 150 mg of triallyl isocyanurate (TAIC) (manufactured by Nippon Kasei) were added. Was blended. The obtained fluoropolymer dispersion composition was applied on a glass plate, air-dried for 30 minutes, and then dried in an oven set at 80 ° C. for 30 minutes to form a coating film. After that, the coated glass plate is sealed with aluminum foil and baked at 170 ° C for 10 minutes.After cooling, the aluminum foil cover is also taken out and immersed in pure water to peel off the glass plate thin film. Immediately removed from the water, air-dried at room temperature. The obtained thin film had a thickness. When the obtained thin film was immersed in pure water at room temperature for 15 hours, the swelling ratio (volume ratio) of the film was 10% or less.

[0090] Comparative Example 1

When the same operation as in Example 2 was performed except that Perhexa 25B and TAIC were not added, the swelling ratio of the membrane was 20%.

[0091] Example 3

Perfluoro (ethyl ether) sulfol fluoride (PFSF, CF = CFO

2

(CF CF SO F) was changed to 49 g, and the procedure was as in Example 2.

2 2 2

The PFSF content, from which the NMR force was also estimated, was 23.4 mol%, and the swelling ratio of the film was 160%.

[0092] Comparative Example 2

When the same operation as in Example 3 was performed except that Perhexa 25B and TAIC were not added, when the obtained thin film was immersed in pure water at room temperature for 15 hours, the film was dissolved in water.

[0093] Example 4

50 ml of the fluoropolymer dispersion obtained in Example 3 from which low molecular substances were removed and purified and concentrated by centrifugal ultrafiltration, 100 ml of pure water, and 20 mg of ammonium persulfate were placed in the same autoclave, and After sufficiently replacing the reaction vessel with xafluoropropylene [HFP] gas, pressurize the HFP gas to 20 g at 4 ° C and IMPa to TFE, then raise the temperature to 60 ° C, and co-polymerize TFE and HFP. The coalescence was block polymerized. After the pressure dropped from 1.6 MPa in the initial stage to 1.5 MPa after 5 hours, the temperature was lowered to 20 ° C or less, and the pressure was released to obtain 165 ml of an aqueous dispersion of a fluorine-containing polymer. The obtained reaction solution was further centrifuged with Centriprep YM-10 (manufactured by Amicon). ), Low molecular substances were removed and the fluoropolymer was purified and concentrated by centrifugal ultrafiltration. While stirring 10 ml of the obtained aqueous fluoropolymer dispersion, 12 ml of triethyl phosphate and 5 ml of isopropanol, 50 mg of perhexa 25B (manufactured by NOF Corporation), 50 mg of triaryl isocyanurate (TAIC) (manufactured by Nippon Kasei Corporation) 150 mg. The obtained fluorine-containing polymer dispersion composition was applied on a glass plate, air-dried for 30 minutes, and then dried in an oven set at 80 ° C. for 30 minutes to form a coating film. After that, the glass plate with the coating was sealed with aluminum foil, baked at 170 ° C for 10 minutes, heated at 295 ° C for 5 minutes, cooled, taken out of the aluminum foil, and treated with pure water. The thin film was peeled off by immersion in the glass plate, immediately removed from water and air-dried at room temperature. The obtained thin film had a thickness of 15 m. When the obtained thin film was immersed in pure water at room temperature for 15 hours, the swelling ratio of the film was 0. When the ion exchange capacity of the obtained membrane was measured by a titration method, it was 870 gZ equivalent.

[0094] Example 5

Same as Example 3 except that 2 g of CF = CFOCF CF I was used instead of I (CF) I

2 4 2 2 2

Where, the content of PFSF estimated 300 ° C melt NMR force, 23. 0 mol ^_0/0, the swelling rate of the film was 5%.

Industrial applicability

[0095] The fluoropolymer liquid composition of the present invention can be suitably used for, for example, an electrolyte membrane.

Claims

The scope of the claims

[1] A fluoropolymer liquid composition comprising a liquid medium and a crosslinkable fluoropolymer having a crosslinkable functional group (A) a fluoropolymer liquid composition which also has strength,

In the fluoropolymer liquid (A), particles made of a crosslinkable fluoropolymer (PD) having an acid salt type group or an organic group which is converted into a carboxyl group by hydrolysis are dispersed in a liquid dispersion medium. Liquid fluoropolymer dispersion (AD) or a crosslinkable fluoropolymer (PS) having an acid salt type group or a precursor of an acid salt group (PS) Is a fluorine-containing polymer solution (AS) dissolved in an alcohol / water mixed solvent, wherein the acid salt group is a sulfonic acid group, a carboxyl group, -SO NR ² R ³ , -SO NR ⁴ R ⁵

twenty three

R ⁶ R ⁷ , -SO M ¹ , — COON ¹¹ or COOM ² (R ² is a hydrogen atom or

3 1 / L 1 / L

M ⁵ represents, and R ³ represents an alkyl group or a sulfol-containing group. ^{^{^{R 4, R 5, R 6}}} , R 7, R 8

1 / L

, R ⁹ , R ^1C> and R ¹¹ are the same or different and represent a hydrogen atom or an alkyl group,

M ² and M ⁵ represents a metal whose valence is L. The L-valent metal is a metal belonging to Group 1, 2, 4, 8, 11, 12, or 13 of the periodic table. ) And

The precursor of the acid type salt group is -SO F, -SO NR ²² R ²³ (R ²² and R ²³ are the same or

twenty two

Differently represents an alkyl group. ) Or an organic group that is converted to a carboxyl group by hydrolysis.

A fluorine-containing polymer liquid composition, comprising:

[2] The acid 'acid salt type group, the precursor of the acid' acid salt type group, and the organic group which is converted into a carboxyl group by hydrolysis are represented by the following general formula (I)

-0- (CF CFY ¹ — O)-(CFY ² ) (I)

2 n m

(In the formula, Y ¹ represents a fluorine atom, a chlorine atom or a perfluoroalkyl group. N represents an integer of 0 to 3. The n number of Y ¹ may be the same or different. Y ² represents a fluorine atom or a chlorine atom, m represents an integer of 115. m Y ² may be the same or different! ), Which is bonded to the fluoroether side chain represented by).

2. The fluoroether side chain is one in which a carbon atom constituting a perfluoroethylene unit in the main chain of the crosslinkable fluoropolymer is ether-bonded. A liquid composition of a fluoropolymer.

[3] The crosslinkable fluoropolymer has the following general formula (II)

CF = CF-0- (CF CFY ¹ — O) — (CFY ² ) —A (II)

2 2 n m

(Wherein, Y ¹ represents a fluorine atom, a chlorine atom or a perfluoroalkyl group. Η represents an integer of 0 to 3. η 個¹ may be the same or different. Υ ² represents a fluorine atom or a chlorine atom, m represents an integer of 1 to 5. m Y ² may be the same or different! A is —SO X, —COOM ³ or hydrolyzed

2 1 / L

1 / L, -NR ¹³ R ^14, or ^{^{^{^{ONR 15 R 16 R 17 R 18}}}} (R 13 and R ¹⁴ are the same or different, a hydrogen atom, an alkali metal, an alkyl group or sulfo -. Represents a Le-containing group M ³ and M ⁴ represents an L-valent ^{^{^{metal. R 1 5, R 16,}}} R 17 and R ¹⁸ are the same or different, represented by a representative.) a hydrogen atom or an alkyl Le group having a carbon number of 1 one 4 3. The fluorine-containing polymer liquid composition according to claim 1, which is a fluorine-containing polymer precursor obtained by polymerizing a fluorofluoroether derivative, or derived from the fluorine-containing polymer precursor.

[4] The fluorine-containing polymer according to claim 3, wherein the fluorine-containing polymer precursor is a binary copolymer or more obtained by polymerizing a fluorovinyl ether derivative and a fluorine-containing ethylenic monomer. Liquid composition.

[5] The fluoropolymer liquid according to claim 3 or 4, wherein Y ¹ is a trifluoromethyl group, Y ² is a fluorine atom, n is 0 or 1, and m is 2. Composition.

[6] The organic group which is converted to a carboxyl group by hydrolysis is COOR ¹² (R ¹² represents an alkyl group) or CONR ²⁴ R ²⁵ (R ²⁴ and R ²⁵ may be the same or different and have an alkyl group or Represents a hydrogen atom.) The liquid fluoropolymer liquid composition according to claim 1, 2, 3, 4, or 5.

[7] The crosslinkable functional group is a cyano group or a crosslinkable carboxyl group,

The fluoropolymer liquid composition is composed of a fluoropolymer liquid (と) and a crosslinking agent (更に),

The crosslinking agent (Β) has the following general formula (III)

[Chemical 1] (III)

(In the formula, one of R ¹⁹ and R ² ° represents NH and the other is NH NH—Ph OH or

twenty two

— Indicates SH. Ph represents a ferul group. R ²¹ is —SO — O CO—, carbon number 11

2

6 represents an alkylene group, a perfluoroalkylene group having 1 to 10 carbon atoms or a single bond. 7. The fluoropolymer liquid composition according to claim 1, 2, 3, 4, 5, or 6, which is a crosslinking agent (B1) represented by the following formula:

[8] R ¹⁹ and R ² are forces that are both NH, or one is NH and the other is NH—P

twenty two

8. The fluoropolymer liquid composition according to claim 7, wherein h is h.

[9] The crosslinkable functional group is -1 or -Br,

The fluoropolymer liquid composition comprises a fluoropolymer liquid (A) and a crosslinking agent (B),

The fluoropolymer liquid composition according to claim 1, 2, 3, 4, 5, or 6, wherein the crosslinking agent (B) is a polyfunctional unsaturated compound.

10. The fluorinated polymer liquid composition according to claim 9, wherein the polyfunctional unsaturated compound is triallyl isocyanurate.

[11] The fluoropolymer liquid composition is composed of a fluoropolymer liquid (A) and at least one selected from the group consisting of methanol, ethanol, propanol and tetrafluoropropanol. 11. The fluoropolymer liquid composition according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, which is useful as C).

[12] The fluoropolymer liquid composition according to any one of claims 1, 2, 3, 4, 5, 6, 7, and 8 comprising a fluoropolymer liquid (A) and a film-forming auxiliary (D). The fluorinated polymer liquid composition according to any one of 9, 10 or 11, wherein

The fluorine-containing polymer liquid composition which is an organic liquid in which the film-forming auxiliary (D) is compatible with water and has a boiling point of more than 100 ° C and not more than 300 ° C.

[13] The precursor of the acid salt group is -SO NR ^{2 23} (R ²² and R ²³ are the same as described above), or An organic group that hydrolyzes and converts to a carboxyl group,

13. The fluorine-containing agent according to claim 12, wherein the film-forming auxiliary (D) is (1) a phosphate ester, (2) a monohydroxyether of an ethylene oxide oligomer, and Z or (3) a cyclic amide or a cyclic amide derivative. Polymer liquid composition.

[14] The fluorine-containing polymer liquid composition according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, comprising a fluorine-containing polymer liquid (A) and further comprising an active substance (E). 14. The fluorine-containing polymer liquid composition according to 10, 11, 12 or 13.

[15] The crosslinkable fluoropolymer has a sulfonic acid group or a carboxyl group, or a salt of the sulfonic acid group or the carboxyl group,

SO X ^ X ¹ of the fluoropolymer precursor represents a halogen atom. ) Or CO

2

z ¹ ^ ¹ represents an alkoxyl group. ) Is obtained by hydrolyzing) in the presence of water, the fluorine-containing product according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14. Polymer liquid composition.

[16] The fluoropolymer liquid (A) is a fluoropolymer liquid dispersion (AD),

The solid content concentration of the fluoropolymer liquid dispersion (AD) is from 2 to 80% by mass. Claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 16. The fluoropolymer liquid composition according to item 14, 14 or 15.

[17] The fluoropolymer liquid dispersion (AD) is a fluoropolymer aqueous dispersion (ADA) in which the liquid dispersion medium is an aqueous dispersion medium,

17. The fluoropolymer liquid composition according to claim 16, wherein the aqueous dispersion medium has a water content of 10 to 100% by mass.

[18] The fluoropolymer solution (A) is a fluoropolymer solution (AS),

The crosslinkable fluoropolymer (PS) is claim 1 is 0. 1- 10 mass ^_0/0 of the fluoropolymer liquid composition, 2, 3, 4, 5, 6, 7, 8, 9, 16. The fluoropolymer liquid composition according to 10, 11, 12, 13, 14, or 15.

[19] The fluoropolymer liquid composition according to claim 1, 2, 3, 4, 5, 6, Ί, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18 After applying to the material or impregnating the porous material, the liquid medium is removed and cross-linking treatment is performed to produce a fluorine-based cross-linked product A method for producing a fluorinated crosslinked product, characterized in that:

[20] After applying the fluoropolymer liquid composition according to claim 9 or 10 to a substrate or impregnating a porous material, the liquid medium is removed, and crosslinking is performed using a peroxide conjugate as a crosslinking reaction initiator. Producing a fluorinated crosslinked product by performing treatment

A method for producing a fluorinated crosslinked product, characterized in that:

21. The method for producing a fluorine-containing crosslinked product according to claim 19, wherein the crosslinking treatment is a crosslinking treatment using high energy.

22. The method for producing a fluorine-containing crosslinked product according to claim 21, wherein the crosslinking treatment using high energy is performed by heating, radiation irradiation, electron beam irradiation, or light irradiation.

23. The method for producing a fluorine-containing crosslinked product according to claim 19, 20, 21 or 22, wherein the fluorine-containing crosslinked product includes an active substance-fixed crosslinked product containing the active substance (E).

24. The method for producing a fluorine-containing crosslinked product according to claim 23, wherein the active substance (E) is a catalyst.

25. The method for producing a fluorine-containing crosslinked product according to claim 24, wherein the catalyst is a metal containing platinum.

[26] The active substance-fixed crosslinked body is an electrode body for a solid polymer electrolyte fuel cell.

26. The method for producing a fluorine-containing crosslinked product according to any one of items 24 to 25.

[27] The method for producing a fluorine-containing crosslinked product according to claim 19, 20, 21, or 22, wherein the fluorine-containing crosslinked product is an electrolyte membrane.

[28] The fluorinated crosslinked product is a membrane electrode assembly (MEA) in which an electrode assembly for a solid polymer electrolyte fuel cell and an electrolyte membrane are joined together. The method for producing a fluorine-containing crosslinked product according to the above.